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I took a look at this after it was mentioned on Hacker News two weeks ago and ended up building this map of all the DSM 1m data: https://houseprices.io/lab/lid

by hanoz 11y ago

I took a look at this after it was mentioned on Hacker News two weeks ago and ended up building this map of all the DSM 1m data: https://houseprices.io/lab/lidar/map https://houseprices.io/lab/lidar/map I've been quite fascinated to discover how many mysterious lumps and bumps are to be found all over the country, often with no apparent explanation in aerial photo maps, and to my great surprise I find myself cultivating an interest in armchair archaeology. I've stumbled across a few features which on further research have turned out to be sites of note, a couple of which were only discovered in recent years, which is quite exciting. Next mission is to discover something completely unknown. In fact I could do with some help interpreting some features if anyone here has any experience in this area. Here's a couple of well known sites: https://houseprices.io/lab/lidar/map?ref=SU1224642189 https://houseprices.io/lab/lidar/map?ref=SU1224642189 (Stonehenge) https://houseprices.io/lab/lidar/map?ref=SU1025569962 https://houseprices.io/lab/lidar/map?ref=SU1025569962 (Avebury) A few of my 'discoveries': https://houseprices.io/lab/lidar/map?ref=ST5895844810 https://houseprices.io/lab/lidar/map?ref=ST5895844810 (Medieval and Iron Age/Roman field systems near Croscombe, Somerset) https://houseprices.io/lab/lidar/map?ref=NY7217242430 https://houseprices.io/lab/lidar/map?ref=NY7217242430 (Potential henge near Alston, Cumbria) https://houseprices.io/lab/lidar/map?ref=SX1025261066 https://houseprices.io/lab/lidar/map?ref=SX1025261066 (Roman Fort near Restormel Castle, Cornwall) A couple of things I'm not sure about: https://houseprices.io/lab/lidar/map?ref=ST4580543091 https://houseprices.io/lab/lidar/map?ref=ST4580543091 https://houseprices.io/lab/lidar/map?ref=TL2327777126 https://houseprices.io/lab/lidar/map?ref=TL2327777126

macca321 11y ago
Cool! How come my house (and much of central london) is missing?
- hanoz 11y ago
  Sorry to hear about your house, my entire principality is missing, as the Welsh data is now looked after by the devolved equivalent agency, Natural Resources Wales. Happily it appears that's due to be released on November 2nd (http://naturalresources.wales/lidar?lang=en http://naturalresources.wales/lidar?lang=en) so hopefully I'll be able to incorporate that shortly after, depending on what it looks like. The current map is built with all the available DSM (Digital Surface Model) 1m resolution data. It appears the coverage is focused on coast and rivers, which makes sense in light of the Environment Agency's flooding remit. There's more coverage available to download at 2m (covering approximately half of the 1m gaps at a guess) and some small patches available at 50cm and 25cm resolutions.
  - meigwilym 11y ago
    Looking forward to downloading this. By the way: Wales is a country, not a principality. /pedant
    - seanf 11y ago
      Ancient flamewar? https://en.wikipedia.org/wiki/Principality_of_Wales https://en.wikipedia.org/wiki/Principality_of_Wales
      - mynameismonkey 11y ago
        Shwmae, (third?) Welshman checking in. The legal entity that was a Principality ended in 1542, but the P word has stuck over the centuries as a sort of colloquial reference, strongly enough that even ISO only got it right a few years ago. Some of us get offended by it, but mostly only when the Saxons next door use the term.
        pbhjpbhj 11y ago
        Wales was annexed to England and then formally incorporated by the Laws in Wales Act, viz (quoting Wikipedia, apparently quoting the LiW Act 1535): >"That his said Country or Dominion of Wales shall be, stand and continue for ever from henceforth incorporated, united and annexed to and with this his Realm of England;" // So, yes, Wales ceased to be recognised as a principality and instead the lands that formed the area at the time called Wales were, according to Henry VIII, to be referred to only as England. Wasn't this also when English was established as the language to be used in legal proceedings? IIRC the Welsh Language Act 1993 was what changed this situation? I've yet to find definitive details of when Wales officially became a country. It's always struck me that prior to annexation it was only a loose confederation of principalities and that not all of what we now call "Wales" was not a part of the possessions of the English crown. It seems Wales, perhaps first defined by the invading Romans, was then created as an entity only by the English crown's definition of the area in which "Welsh" courts could act. Do you have any input on this?
DanBC 11y ago
The Land Registry and OS maps have more data, and it's a shame they're aren't easily online. It's interesting to compare across Google Maps. Grid reference: SO9644600362) near Coates (Gloucestershire) is an old roman fort. https://www.google.co.uk/maps/@51.7010323,-2.0505876,1017m/data=!3m1!1e3?hl=en https://www.google.co.uk/maps/@51.7010323,-2.0505876,1017m/d... EDIT: And the big lumps north of that are from the canal tunnel. These do not show on the Google map.
scoot 11y ago
Nice job on the viewer. It would be cool to be able to toggle between (or have an overlay of) Ordnance Survey (or similar) data on known archeological features, and a google style aerial view. Couple this with he ability to post and discuss interesting features, it could enable the "crowd-sourcing" of topological archeology.
- hanoz 11y ago
  Thank you, yes I should definitely look into adding both those facilities. In the meantime, it is possible to compare other maps in a clunkier way by tapping to bring up a link to a variety of other sources via Wikipedia's GeoHack tool.
boxfire 11y ago
You can make the further out zooms look better (not salt and pepper like) by using a sinc filter with a 5 or more lobes when to generate those layers. It looks like there is just some simple nearest neighbor or bilinear filtering happening, which is the source of the saltiness.
- hanoz 11y ago
  Oh nice tip, thank you very much. Yes, salt and pepper is a good description and they could definitely do with less of it. I have some reading up to do it seems.
fapjacks 11y ago
Unreal. A couple of years ago, I was smoking dope on my couch with my best friend and we came up with exactly this idea. It's so cool you're doing it! Something I've wondered about: How difficult is researching possible explanations? Scanning the data is easy, but (as you mention) those with "no apparent explanation" might be cataloged somewhere. Have you made any effort to track this data down? What are your results? Cool project!
- hanoz 11y ago
  The archaeological explanations I've found so far have typically been the result of googling the name of the nearest village combined with some keywords like "roman", "medieval", "archaeology" etc, and have appeared in disparate sources; council records, parish newsletters, academic publications and the like. It's a new field to me so I'm not sure whether there are any centralised catalogues which would be more useful.
tonylemesmer 11y ago
how did you find those features? was it just serendiptiy?
- hanoz 11y ago
  Just things that caught my eye while panning around, yes. Serendipity might be too strong a word for it, the country seems to be covered in such features.

by hanoz 11y ago

macca321 11y ago

Cool! How come my house (and much of central london) is missing?

hanoz 11y ago
Sorry to hear about your house, my entire principality is missing, as the Welsh data is now looked after by the devolved equivalent agency, Natural Resources Wales. Happily it appears that's due to be released on November 2nd (http://naturalresources.wales/lidar?lang=en http://naturalresources.wales/lidar?lang=en) so hopefully I'll be able to incorporate that shortly after, depending on what it looks like. The current map is built with all the available DSM (Digital Surface Model) 1m resolution data. It appears the coverage is focused on coast and rivers, which makes sense in light of the Environment Agency's flooding remit. There's more coverage available to download at 2m (covering approximately half of the 1m gaps at a guess) and some small patches available at 50cm and 25cm resolutions.
- meigwilym 11y ago
  Looking forward to downloading this. By the way: Wales is a country, not a principality. /pedant
  - seanf 11y ago
    Ancient flamewar? https://en.wikipedia.org/wiki/Principality_of_Wales https://en.wikipedia.org/wiki/Principality_of_Wales
    - mynameismonkey 11y ago
      Shwmae, (third?) Welshman checking in. The legal entity that was a Principality ended in 1542, but the P word has stuck over the centuries as a sort of colloquial reference, strongly enough that even ISO only got it right a few years ago. Some of us get offended by it, but mostly only when the Saxons next door use the term.
      - pbhjpbhj 11y ago
        Wales was annexed to England and then formally incorporated by the Laws in Wales Act, viz (quoting Wikipedia, apparently quoting the LiW Act 1535): >"That his said Country or Dominion of Wales shall be, stand and continue for ever from henceforth incorporated, united and annexed to and with this his Realm of England;" // So, yes, Wales ceased to be recognised as a principality and instead the lands that formed the area at the time called Wales were, according to Henry VIII, to be referred to only as England. Wasn't this also when English was established as the language to be used in legal proceedings? IIRC the Welsh Language Act 1993 was what changed this situation? I've yet to find definitive details of when Wales officially became a country. It's always struck me that prior to annexation it was only a loose confederation of principalities and that not all of what we now call "Wales" was not a part of the possessions of the English crown. It seems Wales, perhaps first defined by the invading Romans, was then created as an entity only by the English crown's definition of the area in which "Welsh" courts could act. Do you have any input on this?

DanBC 11y ago

The Land Registry and OS maps have more data, and it's a shame they're aren't easily online. It's interesting to compare across Google Maps. Grid reference: SO9644600362) near Coates (Gloucestershire) is an old roman fort. https://www.google.co.uk/maps/@51.7010323,-2.0505876,1017m/data=!3m1!1e3?hl=en https://www.google.co.uk/maps/@51.7010323,-2.0505876,1017m/d... EDIT: And the big lumps north of that are from the canal tunnel. These do not show on the Google map.

scoot 11y ago

Nice job on the viewer. It would be cool to be able to toggle between (or have an overlay of) Ordnance Survey (or similar) data on known archeological features, and a google style aerial view. Couple this with he ability to post and discuss interesting features, it could enable the "crowd-sourcing" of topological archeology.

hanoz 11y ago
Thank you, yes I should definitely look into adding both those facilities. In the meantime, it is possible to compare other maps in a clunkier way by tapping to bring up a link to a variety of other sources via Wikipedia's GeoHack tool.

boxfire 11y ago

You can make the further out zooms look better (not salt and pepper like) by using a sinc filter with a 5 or more lobes when to generate those layers. It looks like there is just some simple nearest neighbor or bilinear filtering happening, which is the source of the saltiness.

hanoz 11y ago
Oh nice tip, thank you very much. Yes, salt and pepper is a good description and they could definitely do with less of it. I have some reading up to do it seems.

fapjacks 11y ago

Unreal. A couple of years ago, I was smoking dope on my couch with my best friend and we came up with exactly this idea. It's so cool you're doing it! Something I've wondered about: How difficult is researching possible explanations? Scanning the data is easy, but (as you mention) those with "no apparent explanation" might be cataloged somewhere. Have you made any effort to track this data down? What are your results? Cool project!

hanoz 11y ago
The archaeological explanations I've found so far have typically been the result of googling the name of the nearest village combined with some keywords like "roman", "medieval", "archaeology" etc, and have appeared in disparate sources; council records, parish newsletters, academic publications and the like. It's a new field to me so I'm not sure whether there are any centralised catalogues which would be more useful.

tonylemesmer 11y ago

how did you find those features? was it just serendiptiy?

hanoz 11y ago
Just things that caught my eye while panning around, yes. Serendipity might be too strong a word for it, the country seems to be covered in such features.